Cyclopentenyl alkyl acetic acid



Patented July 17,1928.

UNITED STATES PATENT OFFICE.

306KB ADAKS, OF UBBANA, ILLINOIS, ABSIGNOB T ABBOTT LABdRATOBIES, 0]

NORTH CHICAGO, A. OOBPORATIQH OI ILLINOIS.

GYOLOPENTEKYI ALKYL'ACETIO ACID.

Io Drawing.

gen, such as a metallic element or an alkyl group. i e It has been found that the higher homologs in this series of compounds are more eflicient bactericidally than those lower In the series.

General method of preparation.

The/acids here referred to may conveniently be prepared by first condensing cyclopentenyl chloride with sodiomalonic ester, and isolating the cyclopentenyl malonic ester so obtained; this roduct is then. condensed with an alkyl hali e, in the presence of sodium ethylate, to give cyclopentenyl-alkylmalonic ester. Upon 'saponification to the corresponding malonic acid, and heating to eliminate one of the carboxyl groups, the

A -cyclopentenyl alkyl acetic acids are obmined, and are purified by distillation under reduced pressure.

For example, beginning with cyclopentenyl chloride, the following procedure may be followed in the preparation of the cyclopentenyl alkyl acetic acids.

Ewample I The molecular equivalent of cyclopentenyl chloride is added to 1.25 molecular equivalents of sodiomalonic ester inabsolute alcohol. After the reaction is complete, the alcohol is distilled off, water is added to the residue, and the cvclopentenyl malonic ester is taken up in ether and dried. Upon distillation, it boils at 113118 C. at 5 mm.

To 175 cc. of absolute alcohol, in a flask fitted with a stirrer and condenser, is added 5.8 grams sodium. After the latter has dissolved, 56.5 grams (0.25 mole) of A -cyclm ntenyl malonic ester is added. The conenser is fitted for distillation and 135 cc. of

cooled reflux condenser.

Alpha- A -cyclopentenyl) -undecanoic acid.

Application fled Amlt 25, 1937. Serial 1T0. 215,517.

alcohol is distilled off. After changing the condenser to the upright position, 0.3 gram molecular weight of n-nonyl bromide is added and the mixture refluxed for 48- hours. The alcohol is distilled off and the water added to dissolve the sodium bromide. The layers are separated. and the ester taken up in ether, dried, and distilled under diminished pressure, which yields pure A -cyclopentenyl nonyl malonic ester.

A solution of 17 grams of otassium hydroxide and 0.1 gram molecu ar equivalent of n-nonyl-A -cyclopentenyl malonic ester in 75 cc. of alcohol is refluxed for 24 hours. The solution is diluted with cc. water and distilled until the temperature reaches 98 C. The residue is refluxed for two hours, cooled to 10, and acidified with concentrated hydrochloric acid. The n-nonyl-A cyclopentenyl malonic acid is separated and the aqueous residue extracted with ether. The ether extract is dried, the ether evaporated, and the entire amount of the malonic acid derivative is heated for two hours at MSG-165 (l, in a flask fitted' with an air The alpha-(A?- acid is distilled pressure; it boils at 173- 'cyclopentenyl) -undecanoic under diminished 176 C. at 3 mm.

Other homologs of this series of compounds may be prepared in an entirely similar manner, by substituting the-appropriate alkyl group into the cyclopentenyl malonic ester-as described above, and then proceedmg as outlined. The intermediates and final acids so produced are described in the following table Alpha (A cyclopentenyl) substituted aliphatic acids.

General formula CH=CH Boiling point of the malonic ester.

Boiling oint o! the cid.

142-145 (5 mm). 150-155" (5 mm.),

17mm? (4mm): 178-176" (3mm,).

It is ossible to reverse the method of preparation of the above substituted malonic esters by first introducing the alkyl group, followed'by the cyclopentenyl group.

The. group described acids are only slightly soluble in water, but dissolve in solution of bases, such as sodium hydroxide, to form soluble salts.

The scope of the invention should be determined by reference to the appended claims, said claims being construed as broadly as possible consistent with the state of the art.

I claim as my invention:

1. New compounds of the formula ou=cu on-onun cooz, CIIr-CII:

in which R represents an alkyl group contamlng fire or more carbon atoms, and Z CH=CH J: Lyon-cum) coon H-C g in which R represents an alkyl group containing five or more carbon atoms.

3. As a new medicament,a A -cyclopentenyl nonyl acetic substance, having the formula Iii-CH1 in which Z represents hydrogen, a metallic element or an alykl group.

ROGER ADAMS. 

